Eyewitnesses said the bus was torn apart by the explosion, which happened in the busy Ben Aknoun area of the capital Algiers. The blast left a scene of devastation, with clothing and belongings strewn among wreckage and pools of blood.

But as is always the case when such things happen in the city, security forces were swiftly on the scene, and the site was quickly cleaned up. Algerian morning newspapers had reported that a number of similar bomb attempts had earlier been foiled.

It said they were aimed at embarassing the government, as it was playing host to a delegation from the European Union, the first of its kind since the latest spate of massacres raised widespread international concern. It's been holding talks with government ministers here, and also with leaders of the permitted opposition parties, as well as with Algerian human rights observers, and newspaper editors.

Before leaving, the mission leader, the British Minister of State for Foreign Affairs, Derek Fatchett, said the delegation had achieved progress in its stated aims of continuing a dialogue with the Algerians, and expressing solidarity over the suffering. But any ordinary Algerians who were hoping for some kind of early practical results from the European move, will have been disappointed.

On the issue of an international enquiry into the massacres, Mr Fatchett said the delegation had argued that it was in the Algerian government's interest, to win itself a clean bill of health, by allowing the United Nations to send human rights officials in to make a report. But that argument clearly cut no ice with the Algerian authorities, to the delegation's regret.

The Algerian government did want to press the Europeans to do more to control dissidents given refuge abroad, whom Algiers regards as terrorists. The delegation asked for specific proposals, and they're expecting to hear back by the end of the week.